Some people think PolitiFact's network scorecards can't be taken as a reliable litmus test of network truthfulness. After all, these skeptics say, PunditFact doesn't check every claim by every pundit on the networks.
But today PunditFact broke the news that it does check every claim on the networks (bold emphasis added):
MSNBC and CNN have improved ever so slightly on our TV network scorecards, while Fox News has moved a touch in the opposite direction.So that lends a great deal of credibility to PunditFact's scorecards. After all, if the scorecards are examining all the claims then there's no issue with selection bias. Right?
We last looked at our network scorecards, which examine all the claims made by pundits on air, in September. The scorecards measure statements made by a pundit or a host or paid contributor on a particular network. They do not include statements made by elected leaders, declared candidates or party officials.
Or not. PunditFact added this later on in the article:
As we have said in the past, be cautious about using the scorecards to draw broad conclusions. We use our news judgment to pick the facts we’re going to check, so we certainly don’t fact-check everything. And we don’t fact-check the five network groups evenly.Bless your heart, PunditFact.